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Objective To investigate the distribution of qnr and aac(6')- Ⅰ b-cr genes of clinical isolates resistant to ciprofloxacin in Enterobacteriaceae in Wenzhou. Methods From August 2005 to April 2008 a total of 461 clinical isolates resistant to ciprofloxacin in Enterobacteriaceae (370 isolates of Escherichia coli, 39 isolates of Enterobacter cloacae and 52 isolates of Klebsiella) were collected from the First Affiliated Hospital of Wenzhou Medical College. qnr and aac(6')- Ⅰ b genes were detected by PCR for all the clinical isolates, DNA sequencing was used for qnr and aac(6')-Ⅰ b-cr identification and conjugation experiment was proved to find ways of transmission of antimicrobial resistance. Results Fifteen qnr-positive isolates were detected among 461 Enterobacteriaceae isolates, including 5 qnrA-positive isolates (4 Enterobacter cloacae isolates and 1 Klebsiella ornithinolytica isolate), 4 qnrB-positive isolates( 2 Klebsiclla paeunoniae isolates and 2 Escherichia coli isolates), 6 qnrS-positive isolates(2 Klebsiella pneunoniae isolates and 4 Escherichia coli isolates). Fifty-two among 461 Enterobacteriaceae isolates harbored aac(6')- Ⅰ b-cr gene, including 42 Escherichia coil isolates, 4 Enterobacter cloacae isolates and 6 Klebsiella isolates. DNA sequencing for 15 qnr-positive isolates found they harbored aac(6')- Ⅰ b-cr gene simultaneously. Fifteen qnr-positive isolates were susceptible to imipenem but resistant to some other drugs. Conjugation experiments were successfully carried out in 7 of 15 isolates harbored qnr and aac(6')-Ⅰ b-cr genes, and their resistance to quinolones and aminoglycosides was partly transmitted to the recipient isolates. Conclusion The qnr genes are few in clinical isolates resistant to ciprofloxaein in Enterubacteriaceae in Wenzhou, however the aac(6')- Ⅰ b-cr gene is popular.
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Objective To investigate the prevalence and molecular epidemiology of clinical isolates of plasmid-mediated 16S rRNA methylases-producing Klebsiella pneumoniae. Methods From January 2006 and September 2007, 337 non-replicate clinical isolates of Klebsiella pneumoniae were consecutively collected from inpatients in a teaching hospital in Wenzhou, China. All of the isolates were identified by the automated microbiology systems. MICs of amikacin, gentamicin and tobramycin were determined by agar dilution method. The isolates were investigated for the presence of ESBLs by the CLSI-recommended confirmatory tests. PCR was used to detect 16S rRNA methylase genes, ESBL genes and class Ⅰ integrase gene. The homology of these isolates was analyzed by pulse-field gel electrophoresis (PFGE). Results Sixty-four ( 19. 0% ), 28 ( 8. 3% ) and 55 ( 16. 3% ) of 337 isolates were resistant to gentamicin, amikacin and tobramycin, respectively. Twenty-one (6. 2% ) isolates carried 16S rRNA methylase genes (3 for armA, 13 for rmtB, 5 for both armA and rmtB) and high-level resistant to gentamicin, amikacin and tobramycin ( MICs ≥256 mg/L). Nineteen of 21 isolates with 16S rRNA methylase genes were ESBL producers, blaCTX-M-14-like, blaCTX-M-like and blaSHV-12-like were predominant genotypes of ESBLs. The plasmids of 13 isolates were transferred into the recipients E. co/iJ53. PCR and sequence analysis revealed that blaCTX-M-14-like,blaCTX-M-15-like and blaSHV-12-like were co-transferred with the armA or the rmtB to the recipients. All transconjugants harbored intll and blaTEN-1. Of the 21 isolates, 14 patterns were obtained by PFGE. Conclusion Both horizontal gene transfer and clonal spread were responsible for the dissemination of the rmtB or the armA gene in Klebsiella pneumoniae.
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Objective,This study was designed to evaluate the predictive value of pre-procedure Cardiac troponin I(cTnI)and CRP levels in patients with acute coronary syndrome(ACS)undergoing percutaneous coronary intervention(PCI).Methotis cTnI and CRP were determined on admission in 335 consecutive patients with ACS who underwent primary PCI.Blood samples were obtained within 6-10 h after onset of symptom.The concentration of cTnI was determined by an automated chemiluminescence immunoassay.CRP was measured by immunoassay assay.According to the admission cTnI(＜0.1,0.1-0.5,＞0.5μg/L)and CRP(≤3,＞3 mg/L)divided into different groups.The pre-procedure cTnI and CRP status associated with 30 days cardiac mortality and major adverse cardiac events(MACE.including cardiac death.non-fatal recurrent MI.heart failure.readmission for any reason)were analyzed.The cardiac mortality at follow.uD period of 2 years were analyzed.Results Muhivariate logistic regression analyses revealed preoperative cTnI predicted 30 days cardiac mortality(OR=3.5,95%CI 2.2-5.3,P＜0.01),and recurrent MI rate(OR=1.5,95%CI 1.1-2.6,P＜0.05),independent of other known prognostic factors such as age,gender,hypertension,Hypercholestemlemia,diabetes and smoking.The pre-procedure CRP was independently related to 30 days cardiac mortality(OR=1.6,95%CI 1.1-2.3.P＜0.05),whereas there was no relationship to the MI rate.In ACS,levels of CBP≤3 mg/L,the three different risk groups (cTnI＜0.1,0.1-0.5,＞0.5μL)with corresponding 30 days MACE rates of 4.3%,11.7%,18.8%(X~2=4.829,P=0.028),CRP＞3 mg/L,the three groups mth corresponding 30 days MACE mtes of 5.5%,13.2%,21.1%(X~2=5.862,P=0.015),respectively.Patients were followed up for 2 years,Kaplan-Meier survival analysis demonstrated a significantly reduced survival at 2 years in patients witll a cTnI ＞0.5μg/L(80.0%versus 89.1%for a cTnI of 0.1-0.5μg/L and versus 92.2%flor cTnI＜0.1μg/L;X~2=7.571,P＜0.05 by log-rank).Conclusions The levels of CRP and cTnI in Acs of onset in 6-10 h provide an even better risk stratification after the PCI.and closely correlate with 30 days MACE.Elevated cTnI provides long-term prognostic information regarding cardiac mortality.Therefore.The combination of CRP and cTnI measurement should be taken into consideration for risk stratification to decide about the management strategies in ACS patients.
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Objective To investigate the prevalence of aac(6')-Ib-cr in clinical isolates of Klebsiella pneumoniae.Methods A total of 337 isolates of Klebsiella pneumoniae were isolated from clinical specimens in our hospital from Jan,2006 to Sep,2007.Gentamycin,amikacin or tobramicin was used to screen the isolated with aac(6')-Ib-cr.aac(6')-Ib and class 1 interase gene(intl1)was determined by PcR All PCR products of aac(6')-Ib were sequenced for determination of aac(6')-Ib-cr. MICs of antibiotics were determined by agar dilution method.The ESBLs-producing isolates were determined by the CLSI-recommended confirmatory tests.Conjugation test was used to detect the transfer of plasmid.Results Of the 337 clinical isolates of Klebsiella pneumoniae,64(19.0%),28(8.3%)and 55(16.3%)isolates were resistant to gentamycin,amikacin and tobramycin,respectively.Among 64 gentamycin-resistant isolates,24(37.5%)were positive for aac(6')-Ib-cr,including 13 ciprofloxacin-resistant isolates and 11 ciprofloxacinsusceptible isolates.The prevalence of aac(6')-Ib-cr in ciprofloxacin-resistant and-susceptible isolates were 54.2%(13/24)and 27.5%(11/40).The positive rates of ESBLs and intl1 in the 24 isolates carrying aac(6')-Ib-cr were 79.2%(19/24)and 91.7%(22/24).Plasmids carrying aac(6')-Ib-cr of 13 isolates were successfully transferred to E.coli J53.Plasmids of all transconjugants were positive for aac(6')-Ib-cr and intl1.All transconjugants were ESBL producing strains.Conclusions aac(6')-Ib-cr exists widely in clinical isolates of Klebsiella pneumoniae.aac(6')-Ib-cr and ESBL gene usually coexist in a selftransmissible conjugative plasmid by class 1 integron.
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OBJECTIVE To find out the changes of pathogens and their sensitivity to antibiotics in bile samples of patients with biliary tract infection of our hospital during last six years. METHODS The data of 359 strains of microbes found in 371 patients with positive bile culture from Jan 2001 to Dec 2006 and their sensitivity to antibiotics were statistically analyzed. RESULTS There were 84 and 188 positive samples respectively in 140 samples during the first half of this study (2001-2003)and 231 ones during the second half (2004-2006) as well as 105 and 254 strains cultured. Respectively, Gram-negative bacteria accounted for 60.0%, and 50.8% and Gram-positive cocci 34.3%, and 40.2% and fungi 5.7%, and 9.0%; Escherichia coli was the major one and accounted for 36.2%, and 31.1%, with the increasing incidence of the positive rates of its ESBLs (34.2% vs 60.8%, P